Fri, 01 May 2026 13:56:37 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282145#Comment_282145 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282145#Comment_282145 Sun, 12 Jul 2020 09:05:54 +0100 jms452
After it's rained the inverter (SMA 3600TL) stops generating and says 'isolation resistance - check generator'- I presume this means that the inverter is detecting earth leakage.

After a period (a few hours) of dry and sun the system starts working again which we have been advised suggests that the problem is water ingress.

Given that we have 1.5 years of insurance left we are keen to get this fixed but thought there must be relevant wisdom from people who have solved this sort of issue before on GBF.

To complicate matters our original installer has ceased trading so we'd be looking at a claim on the insurance scheme (iwi.biz).

What does a long lasting fix to this problem look like - (i.e. are we replacing a few exterior connectors or all wiring?) and how painful is the insurance process?

TiA

John]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282147#Comment_282147 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282147#Comment_282147 Sun, 12 Jul 2020 09:19:17 +0100 tony
If you can get at it easily, I would cut off half the panels, if you have several strings find which one the fault is in then cut that circuit in half with a flying lead, repeating til only one panel or connector, or lead left.

If only one panel not working cut it out of the system]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282150#Comment_282150 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282150#Comment_282150 Sun, 12 Jul 2020 10:05:28 +0100 Peter_in_Hungary
Then is the fault repeatable with a hose pipe - it makes fault tracing much easier if you don't have to wait for rain!

If it is covered by the insurance get a professional to undertake the repair (probably with agreement from the insurance co.)

If the insurance co. don't want to know either a professional fixer or diy but eventually you (or the Mr. fixit) will need to get on the roof to isolate the sections/panels and fix the problem.

As an after thought - if the fault is repeatable with a hose pipe then perhaps the easy way to isolate the fault down to a few panels would be to hose a section at a time.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282154#Comment_282154 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282154#Comment_282154 Sun, 12 Jul 2020 10:17:51 +0100 jms452

Tony - We have two strings so this bit is fairly easy - at least I'll know which aspect to put the scaffold on.

Peter - Hose pipe ideal is interesting - intermittent faults are a pain!

What is people's experience of solar PV insurance companies - helpful or anything to avoid maying our a penny?

Is it worth just replacing all the connectors - if one has failed in 8 years then will more fail over time... - is this a well know issue?]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282162#Comment_282162 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282162#Comment_282162 Sun, 12 Jul 2020 15:27:37 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282280#Comment_282280 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282280#Comment_282280 Fri, 17 Jul 2020 08:19:46 +0100 revor https://talk.electricianforum.co.uk/ is good have a DIY section and lot of the contributors are very willing with their assistance. There are solar pv specialist on there as well.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282283#Comment_282283 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282283#Comment_282283 Fri, 17 Jul 2020 10:30:35 +0100 CWatters https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282287#Comment_282287 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282287#Comment_282287 Sat, 18 Jul 2020 11:22:35 +0100 jms452 10 years of its installation will be corrected by free repair or replacement provided that it has been used and maintained in accordance with the manufacturers instructions and has not been abused or misused in any way'.

If the insurance prooves too painful my current thinking is that I'll investigate where the problem is without interfering with the system (e.g. with localised artificial rain - thanks PiH) then get a solar PV electrician to fix it once I have scaffold up and can point to where the problem lies.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282483#Comment_282483 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282483#Comment_282483 Thu, 30 Jul 2020 22:54:30 +0100 jms452
Applied to the insurance company a couple of weeks ago. Typical of insurance companies they don't make your life easy - I needed to apply to them for a specific form before even making a claim and there was a 30 day time limit on making the claim from the first event (so don't hang around if you have a problem).

After that I got contacted by a (surprisingly helpful risk management company processing my claim) informing me that both the insurers and the underwriters had gone under, but that any remedial work was 90% covered by the Financial services compensation scheme and suggesting a solar repair expert with attached quote.

Said Solar guy took two hours to tighten all the connectors on the roof this morning replacing one that was corroded and poorly attached.

If this doesn't fix it then it gets expensive (scaffold and disassembly) so glad I went down the insurance route as they are clearly on the hook if more action is needed. I'll find out next time it rains heavily.

After the initial claim this was actually surprisingly straightforward.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282492#Comment_282492 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282492#Comment_282492 Fri, 31 Jul 2020 09:04:30 +0100 tony
I am a director of a community PV scheme and we have thousands of panels and no known problems.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282496#Comment_282496 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282496#Comment_282496 Fri, 31 Jul 2020 10:08:50 +0100 Ed Davies Posted By: tonyTightening connectors, were they the push and click onesPresumably the bits which needed tightening were the caps on the back which need to be pretty tight otherwise water gets in and corrodes the contacts. That's far more likely than faults in the wire.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282506#Comment_282506 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282506#Comment_282506 Fri, 31 Jul 2020 23:34:06 +0100 jms452
The connector he replaced was very similar to the one in Ed's photo.

He also tightened all the screws in the DC isolator's wire clamps as apparently these can work loose over the years due to temperature cycling (but ours seemed ok).

Well I'll find out if his hypothesis is correct next it rains.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282508#Comment_282508 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282508#Comment_282508 Fri, 31 Jul 2020 23:46:05 +0100 djh Posted By: jms452Solar guy suspected that the fitters has just hand tightened the screw on caps on the back of the connectors rather than using a tool to get them fully tight. This was on the tails connecting the inverter to the factory made connectors on the panels themselves. Apparently one of the wires came out when he was retrieving it to check if it was tight enough and it was corroded inside.

The connector he replaced was very similar to the one in Ed's photo.

He also tightened all the screws in the DC isolator's wire clamps as apparently these can work loose over the years due to temperature cycling (but ours seemed ok).
I was quite surprised by quite how tight my electrician made the screws in our sockets. He said this was because they would all become looser over time due to thermal effects. So I've made a point of doing things up extra tight ever since, and checking them after a year or two where possible. I also believe his theory about CU fires, which he reckoned were mostly due to the removal of the second screw on connections, so changing the boxes to metal to contain the fire were a pretty brain dead 'solution' to the problem. Reinstating the second screws to eliminate the problem being a more sane approach, IHHO.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282511#Comment_282511 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282511#Comment_282511 Sat, 01 Aug 2020 10:38:01 +0100 Ed Davies Posted By: djhReinstating the second screws to eliminate the problem being a more sane approach, IHHO.Getting rid of screw terminals would be better, IMHO. I just can't see how they can be expected to stay tight long term with no springiness to deal with thermal expansion and contraction, etc. There's a good reason they're not allowed in locations where they can't be inspected (buried in walls, etc) where crimps or spring-type terminals (e.g., Wago connectors) are allowed. It's all very well saying connections in CUs are accessible but how often are they actually inspected in practice? In rental properties probably maybe but for many owner-occupied houses not enough, I'd think.]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282530#Comment_282530 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282530#Comment_282530 Sun, 02 Aug 2020 08:53:45 +0100 revor https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282827#Comment_282827 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282827#Comment_282827 Thu, 13 Aug 2020 10:32:44 +0100 jms452 ]]> https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282830#Comment_282830 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282830#Comment_282830 Thu, 13 Aug 2020 12:13:32 +0100 tony https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282831#Comment_282831 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=16655&Focus=282831#Comment_282831 Thu, 13 Aug 2020 13:38:23 +0100 philedge Posted By: djh I also believe his theory about CU fires, which he reckoned were mostly due to the removal of the second screw on connections, so changing the boxes to metal to contain the fire were a pretty brain dead 'solution' to the problem. Reinstating the second screws to eliminate the problem being a more sane approach, IHHO.

Im not sure your sparky is thinking things through!! The change to a single screw is largely due to the introduction of a totally different clamping arrangement. Twin screw connections typicaly have the screws bearing directly on the conductors which in the case of stranded cable like meter tails spreads the strands and diminishes the contact area.

Modern single screw set ups typically have a clamp that encloses all the strands and the screw tightens the clamp and doesnt actually come into contact with the conductors.]]>